Depends whether people accept or deny connection with the symbols. Good example is Germany in the pre-war time and after that. In the 1930's the swastika "hakenkreutz" symbol became a national symbol for the Germany and for many people it was a great unifying emblem. The problem lies in the underlying nationalist extremism beneath. The symbol itself was not harmful, the ideas were.
Thus we can say the symbols, like the flag of the USA tend to unite people in some way, but also lead people to forgetting that the "other" people have their rights too, it makes people arrogant or hateful againgst others who do not believe in the same nationalist ideals.
Soon after the WW2 in the Germany the previous nationalist symbols were so much hated that even no children were named "Adolph" for example.